extract published field for convenience

apps/api/migrations/0008_invention_visibility.sql

@@ -0,0 +1,21 @@
+-- Break the two visibility flags out of the invention JSON blob into queryable
+-- generated columns, the same way 0003 did for `IsFeatured`. `IsPublished` and
+-- `HideFromPlayer` are always tested together — every feed, the search/browse list and
+-- the per-room list ask for "published and not hidden" — so they move together.
+-- Generated from src/inventions-db.ts (SCHEMA_DDL) — keep in sync.
+--
+-- SQLite allows ALTER TABLE ADD COLUMN only for VIRTUAL generated columns (a STORED one
+-- would need rewriting existing rows), which is what we want anyway: the value stays
+-- derived from `data`, so nothing can drift out of sync with it. json_extract of a JSON
+-- `true` is 1, so both columns read 1/0 — and NULL for a blob missing the key, which is
+-- neither 1 nor 0 and so fails both filters exactly as the json_extract predicates it
+-- replaces did. This is a rename, not a behaviour change.
+--
+-- No index: both columns are booleans that are overwhelmingly one value (nearly every
+-- invention is published and not hidden), so an index on them would be read past rather
+-- than used. The selective one is idx_invention_featured, added in 0003, which stays.
+
+ALTER TABLE invention
+  ADD COLUMN is_published INTEGER GENERATED ALWAYS AS (json_extract(data, '$.IsPublished')) VIRTUAL;
+ALTER TABLE invention
+  ADD COLUMN hide_from_player INTEGER GENERATED ALWAYS AS (json_extract(data, '$.HideFromPlayer')) VIRTUAL;